Sibutramine (trade name Meridia in the USA, Reductil in Europe and other countries), usually as sibutramide hydrochloride monohydrate, is an orally administered agent for the treatment of obesity. It is a centrally-acting serotonin-norepinephrine reuptake inhibitor structurally related to amphetamines,although its mechanism of action is distinct.

Sibutramine is manufactured by Abbott Laboratories. It is classified as a Schedule IV controlled substance in the United States.

Interactions
Sibutramine has a number of clinically significant interactions. The concomitant use of sibutramine and monoamine oxidase inhibitors (MAOIs, such as selegiline) is not indicated, as it may increase the risk of serotonin syndrome, a somewhat rare but serious adverse drug reaction.Sibutramine should not be taken less than two weeks after stopping or before starting use of an MAOI. Taking both sibutramine and certain medications used in the treatment of migraines—such as ergolines and triptans—, as well as opioids, may also increase the risk for serotonin syndrome, as may the use of more than one serotonin reuptake inhibitor at the same time.

The concomitant use of sibutramine and drugs which inhibit CYP3A4, such as ketoconazole and erythromycin, may increase plasma levels of sibutramine. Sibutramine has no effect on the efficacy of hormonal contraception.

Dosage
10 mg once daily (usually in the morning), if this proves insufficient the dose may be increased to 15 mg daily after 4 weeks.